A biological tissue adhesive is formed when a water solution containing blood factor XIII and fibrinogen is mixed with a water solution containing thrombin. The rate at which the adhesive sets or hardens principally depends upon the thrombin concentration. The mixture is applied to the laceration site which is to be adhered or protected. Previous methods of application included applying one solution to the site of adhesion and then applying the other solution thereto. The disadvantage of this method is that inadequate mixing occurs at the site to result in setting of the adhesive at the interface between the two solutions, without good adhesion to the adjacent biological surfaces.
Another method of application comprises the premixing of the two solutions in a mixing vessel, whereupon it is drawn into a syringe and then applied to the site to be adhered. This method requires promptness of application since the setting of the adhesive starts when the two solutions are combined. The time from mixing to the time of application to the site must be quite short, and depends upon the concentration of the thrombin solution.
In another method of application, two syringes are clamped together and the output cones are inserted into a Y-piece. When the mixing occurs in the Y-piece, the adhesive setting also occurs therein to plug it up. When the mixing occurs in the needle connected onto the Y-piece, plug-up of the needle causes buildup of pressure in the Y-piece so that the needle may be separated and injected into the field, possibly into the patient. Thus, there is need for a biological syringe system wherein the needle and other parts cannot become inadvertently detached so that no parts are ejected.